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If a machine is never 100% efficient transforming energy into work because part of the energy is converted into heat, does it mean an electric heater is 100% efficient? @showerthoughts@lemmy.world

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[-] userflairoptional@lemmynsfw.com 7 points 9 months ago

Black-body radiation is an interesting argument against 100% efficiency, but couldn't you just extrapolate and argue that the emission will be converted back to heat once it stops reflecting and becomes absorbed?

[-] lemmyng@lemmy.ca 4 points 9 months ago

That's like arguing that trickle down economics is efficient because the money eventually gets into the hands of the poor.

[-] Phil_in_here@lemmy.ca 3 points 9 months ago

That's like arguing that 99% of the light off a heating element is a laser beam directed straight into deep space.

[-] ChonkyOwlbear@lemmy.world 0 points 9 months ago

It depends on the framing of the question a bit. If we are defining 100% efficiency as 100% of electrical energy being converted into kinetic energy (heat) by the device, then that is a no. Some percentage is emitted as EM radiation instead of heat. If they were so then a light bulb or a bomb is a 100% effective heater as well.

[-] CookieOfFortune@lemmy.world 3 points 9 months ago

It depends on what you consider the room: Both a light bulb and a bomb would deliver all their energy around a fully enclosed room. Incandescent bulbs are indeed effective heaters, LEDs just deliver much less energy. And a bomb, by design, is hard to contain in a room.

this post was submitted on 17 Feb 2024
248 points (97.3% liked)

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